Language selection

Search

Patent 1059267 Summary

Third-party information liability

Some of the information on this Web page has been provided by external sources. The Government of Canada is not responsible for the accuracy, reliability or currency of the information supplied by external sources. Users wishing to rely upon this information should consult directly with the source of the information. Content provided by external sources is not subject to official languages, privacy and accessibility requirements.

Claims and Abstract availability

Any discrepancies in the text and image of the Claims and Abstract are due to differing posting times. Text of the Claims and Abstract are posted:

  • At the time the application is open to public inspection;
  • At the time of issue of the patent (grant).
(12) Patent: (11) CA 1059267
(21) Application Number: 218532
(54) English Title: BLEACHING PROCESS
(54) French Title: METHODE DE BLANCHIMENT
Status: Expired
Bibliographic Data
(52) Canadian Patent Classification (CPC):
  • 8/93.11
(51) International Patent Classification (IPC):
  • D06L 4/12 (2017.01)
  • C11D 3/26 (2006.01)
  • C11D 3/39 (2006.01)
  • C11D 3/395 (2006.01)
  • C11D 7/18 (2006.01)
  • C11D 7/32 (2006.01)
  • C11D 7/54 (2006.01)
  • C11D 17/06 (2006.01)
(72) Inventors :
  • DIEHL, FRANCIS L. (Not Available)
  • EDWARDS, JAMES B. (Not Available)
(73) Owners :
  • THE PROCTER AND GAMBLE COMPANY (Afghanistan)
(71) Applicants :
(74) Agent:
(74) Associate agent:
(45) Issued: 1979-07-31
(22) Filed Date:
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data: None

Abstracts

English Abstract




BLEACHING PROCESS
Francis Louvaine Diehl
and
James Byrd Edwards

ABSTRACT OF THE DISCLOSURE
Contacting damp fabrics with a dry, activated
bleaching composition in an automatic dryer results in
improved bleaching and stain removal over dry bleaching
compositions employed in an aqueous laundering bath.


Claims

Note: Claims are shown in the official language in which they were submitted.



The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:

1. A process for removing stains from fabrics in an
automatic clothes dryer during the drying cycle comprising
the steps of :
(1) tumbling damp fabrics at a temperature of from
50°C. to 80°C. in the clothes dryer; and
(2) uniformly distributing an effective amount of
a solid particulate bleaching composition consisting
essentially of a peroxygen bleach having an average
particle diameter below about 200 microns onto the
damp fabrics within the first 10 minutes to 15
minutes of the drying cycle such that the bleaching
composition is able to act in the presence of
water on the damp fabrics prior to evaporation of
the water from the fabrics.
2. A process according to Claim 1 wherein the bleaching
composition consists essentially of a peroxygen bleach and
a peroxygen bleach activator.
3. A process according to Claim 2 wherein the bleaching
composition consists essentially of a bleach selected from
the group consisting of alkali metal perborates and ammonium
perborate, and the activator is 1,3,4,6-tetra-acetyl
glycouril.
4. A process according to Claim 3 wherein the weight ratio
of perborate : 1,3,4,6-tetra-acetyl glycouril is in the range
of from 1:3 to about 30:1.
5. A process according to Claim 1 wherein the bleaching
composition comprises from about 1 part to about 10 parts
by weight of sodium perborate and from about 2 parts to
about 1 part by weight of 1,3,4,6-tetra-acetyl glycouril.

27


6. A process according to Claim 1 wherein the bleaching
composition is evenly distributed on the damp fabrics by
a dispensing means.
7. A process according to Claim 6 wherein the dispensing
means comprises a water-insoluble, closed, flexible, porous
pouch.
8. A process according to Claim 7 wherein the pouch
consists of open pore polyurethane foam having a density
of from about 1.1 lbs/cu. ft. to about 1.3 lbs/cu. ft. and
a thickness of from about 0.15 in. to about 0.35 in., and
wherein the bleaching composition consists essentially of
a mixture of sodium perborate and 1,3,4,6-tetra-acetyl
glycouril, said bleaching composition having an average
particle diameter below about 150 µ.
9. A process according to Claim 8 wherein from about
10 grams to about 50 grams of the bleaching composition is
dispensed onto damp fabrics within the first one-quarter
of the drying operation.
10. A process according to Claim 1 wherein the bleaching
composition has an average particle diameter of from about
25 microns to about 175 microns.

28

Description

Note: Descriptions are shown in the official language in which they were submitted.


. BACKGROUND OF THE I:NVENTION
The present invention encompasses fabric bleaching
compositions and processes adapted for use in an automatic
dryer. More specifically, the process herein employs a
solid, substantially dry,activated peroxygen bleach compo-
sition in an automatic clothes dryer to remove stains
from fabrics. The bleach compositions are formulated to
provide the requisite solubility in the limited amount of
water available from the damp fabrics which are being
dried.
Fabric treating processes and compositions designed
to provide desirable functional and aesthetic berefits to
fabrics are conventionally employed in a washing
machine. Thus, fabric sizings and softening agents,
fabric bleaches and brighteners, and the like, are most
commonly formulated and provided as compositions designed
for use either in an aqueous laundering liquor or in an
aqueous rir.se bath. More recently, the treatment of fabrics




,


'; ' : '

...

16~5~t~
in an automatic clothes dryer has been shown to be an
effective means for imparting desirable properties thereto.
For example, it is becoming common to soften fabrics in an
automatic clothes dryer rather than during the rinse cycle
of a laundering operation.
U.S. Patent 3,701,202 discloses a dispensing means
for use in an automatic clothes dryer and suggests that
fabrics may be softened, bleached, and otherwise desirably
treated in the dryer. However, this patent relates only to
a useful dispenser for fabric treatment compositions and
does not disclose operable compositions which can be employed
therein. U.S. Patent 3,180,037 dîscloses a modified bleaching/
drying apparatus.
~he most familiar method for bleaching fabrics to
remove stains, especially in the context of a home laundering
operation, is to add an oxidizing bleach directly to the
laundering liquor. Liquid hypochlorite solutions are most
commonly employed, but solid peroxygen bleaches are also
- commercially available. Such bleaches are designed for
addition to the laundering bath in conjunction with the
detergent, and provide the desired bleaching action con-
currently with fabric laundering.
While through-the-wash bleaching processes are effective
in most instances, they do suffer from several inherent
drawbacks. For example, the addition of either liquid or
solid bleaches to the 10-21 gallons of water normally
employed in an automatic washing machine substantially
dilutes the bleach, thereby reducing its effectiveness. -
For this reason, the quantities of bleach employed in the




;, . ..


~S~5~
laundering bath must necessarily be high to overcome the
dilution effect. Moreover, certain stains can actually be
- "set" by oxidizing bleaches when used in combination with
a detergent in an aqueous laundering bath. For example,
blood stains and mineral stains can be darkened by some
oxidizing bleaches and become more tenaciously affixed to
the fabrics. In such instances, it is more desirable to
remove these kinds of stains by washing in the absence of
bleach, and to complete the laundering operation by a later
bleaching step. Additionally, many oxidizing bleaches
contain ingredients which are not compatible with certain
components of laundry detergents. Undesirable interactions
can ensue when such bleaches and detergents are commingled
in the laundering liquor.
From the foregoing, it is seen that it would be
desirable to provide a means whereby the bleach user could
conveniently and effectively bleach fabrics other than in
an aqueous laundering liquor.
It has now been found that solid bleaches,
especially peroxygen bleaches, can be employed in the manner
disclosed more fully hereinafter to bleach fabrics in an
- automatic clothes dryer. In a preferred mode,
solid peroxygen bleaches are activated by
means of certain additives and employed in an automatic
dryer to provide substantial bleaching superiority over
dry bleaching compositions employed in a laundering liquor.
Accordingly, it is an object of the present invention
to provide compositions and processes designed to achieve
through-the-dryer fabric bleaching.

~s~ 7
It is another object herein to provide dryer-bleaching
compositions especially adapted for use in conjunction with
the limited amount of water available as a reaction medium
in an automatic clothes dryer.
SUMMARY OF THE INVENTION
In its broadest aspect, the present invention encom-
passes a process for removing stains from fabrics in an
automatic dryer comprising tumbling damp fabrics at a
temperature of from 50C. to 80C. in the clothes dryer;
and uniformly distributing an effective amount of a solid
particulate bleaching composition consisting essentially
of a peroxygen bleach having an average particle diameter
below about 200 microns onto the damp fabrics within the
first 10 minutes to 15 minutes of the drying cycle such
that the bleaching composition is able to act in the presence
of water on the damp fabrics prior to evaporation of the
water from the fabrics.
In a preferred mode, the bleaching composition is
employed in the dryer in a dispensing means which provides
even, yet rapid, distribution of the bleach particles over
all fabric surfaces. A preferred bleaching article used
in the present process comprises a bleaching composition
releasably contained in a porous polyurethane pouch, as
more fully described in Canadian Patent 1,022,113, issued
December 6, 1977.
DESC~IPTION OF THE PREFERRED EMBODIMENTS :
The bleaching process of the present invention is
carried out by contacting damp fabrics with an effective
amount of a solid, powdered bleaching composition of the
type described hereinafter. It is an essential feature

f~

of the present process that the fabrics to be bleached be
damp when contacted by the bleaching composition, inasmuch
as water provides the reaction medium in which the bleaching
process occurs. Accordingly, the bieaching compositions
employed herein must have some solubility in water. More-
over, the compositions herein are provided as finely
divided particles having an average diameter ranging up to
- about 200 microns (~), preferably have a diameter of from about
25 ~ to about 175 ~, most preferably 100 ~ to about
10 150 ~. The small particle size of the bleaching compositions
provides rapid dissolution in the limited amount of water
present in the damp fabrics. Such rapid dissolution is
preferred, since the water is constantly being removed from
the fabrics by the action of the dryer.
The bleaching compositions employed in the present
process are specifically formulated to bleach and remove
stains from fabrics in an automatic clothes dryer. Non-
limiting examples of such compositions are as follows.




..... .

2~7
sl~ehi~ Compoa~t~orl -;
T~e bleaching compositions employed herein can be any
of a variety of solid, water-soluble materials known in
the art to be safe and effective for removing stains
from fabrics. The solid peroxygen bleaches are preferred
for use over chlorine bleaches, inasmuch as peroxygen
bleaches are less likely to damage fabric dyes. Mixtures
of bleaches and bleach/activator mixtures can also be
employed as the bleaching compositions herein.
Peroxygen bleaches useful herein include the common
inorganic peroxy-compounds such as the alkali metal and
ammonium perborates, percarbonates, monopersulfates and
monoperphosphates. It is well-known that these inorganic
peroxygen bleaches exist as various hydrates, but the degree
of hydration is not important to the practice of the present
invention. Examples of these peroxygen bleaches include
the sodium and potassium perborates, the sodium and potassium
percarbonates, and complex per-salts such as KHSO4-K2SO4.2KSO5,
marketed under the trademark Oxone. The water-soluble `
perborates, especially in combination with an activator, are ;
particularly preferred herein on the basis of bleaching
performance, fabric safety and availability.
Solid, water-soluble organic peroxy acids, or the
water-soluble, e.g., alkali metal, salts thereof of the
general formula O
HO-O-C-R-YH
wherein R is a substituted or unsubstituted alkylene or
arylene group and Y is
o o O
e O O _s-o or O-C-O-O-
O

-- 6 --

.~,,

- l~iS~

or any other group which yields an anionic group in aqueous
solution are useful herein. These organic peroxy acids
and their use in combination with activators as highly
water-soluble, micellar bleaches are more fully described
in U.S. Patent 3,749,673.
The mixtures of organic peroxy acids and persulfate
bleaches described in U.S. Patent 3,773,673, are also
higly water-soluble and useful in the present invention.
The above peroxygen bleaching compounds and mixtures
can be used singly herein to bleach fabrics. However,
various bleaching activators can be advantageously employed
to enhance bleaching performance. The use of such activators
is especially preferred when the inorganic peroxygen bleaches
Ore employed in the bleaching composition herein. While
not intending to be limited by theory, the need for such
activators arises due to the relatively short time
available for effective bleaching in the automatic dryer.
The bleaching compositions useful in an automatic dryer are
designed to act while there is sufficient water remaining
on the fabrics to provide a reaction medium in which the
bleaching reaction can occur. Accordingly, any m~ans
whereby the bleaching composition is made more readily
soluble and reactive in the limited amount of available
water is of advantage in a through-the-dryer bleaching
compositior
Inorganic peroxygen bleaches can be employed in com-
bination with various solid activators and used as the
bleaching compositions herein. Suitable activators for a
wide variety of inorganic bleaches are set forth in U.S.
30 Patent 3,130,165. In particular, such activators include
various esters of phenols or substituted phenols with


alpha-chlorinated lower aliphatic carboxylic acids, such
as chloracetic acid or alpha-chloropropionic acid, said
esters containing no ester group of any acid other than
alpha-chlorinated lower aliphatic carboxylic acids.
The alkali metal perborates, especially sodium
perborate, and ammonium perborate constitute a prefer,red,
safe and effective class of bleaches herein when used in
combination with an activator. Many perbcrate bleaching
activators are known in the art. Materials such as the
acylphosphonic acid esters, N,N'-diarylsulphamides, carb-
oxylic acid anhydrides, N-acylamides, N-acylated heterocycles,
acylhydroxylamines and other like compounds which readily
acylate the peroxy compounds are well-recognized perborate
activators. `
Included among such perborate activators are tetra- ~-
acetyl methylenediamine, acetyl esters of sodium phenol
sulfonate, chloroacetylsalicylic acid, l-phenyl-3-acetyl ~ -
hydantoin, tetraacetyl ethylenediamine, ~-D-glucose penta-
acetate, p-phenylene diacetate, tris-(acetyl) cyanuric
acid, N-methyl-N-benzoyl-p-toluene sulfonamide, benzoyl
chloride and N-benzoyl imidazole. Other perborate activators
are listed in U.S. Patents 3,177,148 and 3,779,931.
A most highly preferred perborate activator herein is
1,3,4,Ç-tetra-acetyl glycouril, abbreviated TAGU. TAGU
can be prepared in the manner set forth in Henkel Referate
1973 (8), 28 - 33.
It is to be recognized that other solid, water-soluble
bleaching compositions suitable for use herein can be
prepared by admixing inorganic and organic bleaches.
Examples of such mixed bleaches include sodium perborate/
p-methoxyperbenzoic acid, and the like. Such mixed bleaches


l~S'~t;'7
can optionally be activated, for example, by TAGU.
The activated bleaching compositions herein can
contain the activator in either catalytic amounts or in
proportions of bleach : activator which are more nearly
stoichiometric ratios. As noted above, many perborate
activators appear to function by an acylation reaction
and are not catalytic in the accepted sense of that term.
In such instances, lt is well-recognized that sufficient
activator is employed to satisfy the stoichiometric require-
ments of the bleaching reaction.
A preferred bleaching composition for use herein
comprises sodium perborate and TAGU at a weight ratio of
perborate : TAGU of from about 1:3 to about 30:1. A





~5~ ~j7

highly preferred bleach composition comprises from about 1
part to about 10 parts by weight of sodium perborate and
from about 2 parts to about 1 part by weight of TAGU.
Optional Components
The fabric bleaching compositions herein can optionally
contain minor proportions (i.e., 0.1% to about 15% by weight)
of various ingredients which provide additional fabric
conditioning benefits. such optional ingredients include
perfumes, anti-static agents, fumigants, bactericides,
fungicides, optical brighteners, and the like. Specific
exa~ples of typical solid, water-soluble additives useful
herein can be found in any current Year Book of the American
Association of Textile Chemists and Colorists. Such
additional components can be selected from those compounds
which are known to be compatible with the bleaches and
activators employed herein, or can be coated with water-
soluble coatings such as solid soaps, and the like, and
thereby rendered compatible.
Useful optional ingredients herein include C8-C20
amines, imidazolines, and quaternary ammonium salts widely
recognized for use as fabric softening and anti-static agents.
Specific examples of such materials include the mixed tallow-
alkyl amines, di~tallowalkyldimethylammonium chloride, and
the like.
The water-soluble silicate matérials recognized in
the art as corrosion inhibitors can be advantageously
employed in the present compositions at levels of about 5%
by weight.



:~ - 10 -

.L~5~ i7
The ~ater-soluble, solid optical brighteners, especially
bis~(styrylsulfonate)biphenyl, can advantageously be employed
in the present compositions to provide an added brightening
effect on the bleached fabrics.
~ t will be recognized that any of the foregoing types
of optional components can be provided in a solid, particulate
form which can be dispensed onto the damp fabrics concurrently
with the bleaching composition herein to provide the desired
additional fabric treatment benefits.
The compositions herein can be simply sprinkled onto
the fabrics to be bleached. In a preferred mode, the compo-
sitions herein are evenly, yet quickly dispensed onto the
fabrics to be bleached in the dryer by a dispensing means.
A preferred dispensing means comprises a receptacle for the
bleaching composition, which, in combination with the
bleaching composition, comprises a bleaching article designed
for convenient and effective use in an automatic dryer.
Receptacles which are useful as bleach dispensers in an
automatic dryer are described more fully hereinafter.




-- 11 --

~s~
Receptacle
The article herein comprises a water-insoluble, closed
receptacle containing within its cavity a bleaching compo-
sition. The receptacle has at least one opening in
its walls through which the bleaching composition is
released. Inasmuch as the receptacle is to be used in an
automatic dryer, it is comprised of a heat resistant material,
or a material which can be rendered heat resistant at dryer
operating temperatures. Moreover, the receptacle is fashioned
from a material which is resistant to oxidation by the bleach-
ing composition contained therein, both at ambient and dryer
operating temperatures. Since the article is designed for
use in contact with damp clothing, it is made from a water-
insoluble material. The receptacle herein can be made from
open-weave cotton, polyester, and the like, cloth. The
open-weave structure can be chosen to provide controlled
release of the bleaching composition.
Preferred receptacles for use herein are fashioned
from cellular foam materials having a plurality of passages
from inner to outer surfaces. Such foams are known in the
art as "open pore" or "open cell" foams, and have a large
proportion of cells which are interconnected, thereby
providing passageways, or "pores", through the interconnecting
cells. Open pore foams are distinguished from "closed pore"
cellular foams in which the closed pore structure substantially
isolates the individual cells.
Open pore foams can be made from polystyrene, poly~
urethane, polyethylene, poly-(vinyl chloride) cellulose -



- 12 -


. . .

s~i'7
acetate, phenol-formaldehyde and other foamed polymerlc
materials such as cellular rubber. Many of these foams
and their method of manufacture are disclosed in standard
references such as the Encyclopedia of Polymer Science and
Technology, Interscience Publishers, John Wiley & Sons,

-




Inc. (1965).
Preferred materials for preparing the receptacles
herein are open pore polyurethane foams widely known in
the art. The open pore polyurethanes are resistant to heat,
oxidation and water, and can be prepared in a variety of
pore "sizes". The preparation of many recently developed
foams is described in the text, Cellular Plastics Recent
Developments (1970), Johnson, Noyes Data Corporation and
in the Encyclopedia of Polymer Science and Technology, supra.
In general, urethane foams are prepared by polymerizing
diisocyanates and hydroxyl-terminated polyethers or poly-
esters. Foaming is accomplished by including water and
optional foaming agents in the reaction system, and the
reaction between the isocyanate and water releases carbon
dioxide gas which foams the polymer.
The foamed receptables herein provide controlled
release of the particulate bleaching composition during
the drying cycle. The controlled release insures uniform

and measured dispensing of the bleaching composition onto
the surfaces of all fabrics w,thin the dryer. More speci-
fically, during the drying operation the bleaching composi-
tion sifts through the plurality of passages in the walls
of the




... . . . .

~6)5~j7

receptacle. This sifting action is facilitated by the
tumbling action of the dryer.
Water is required to provide a reaction medium for
the bleaching composition, and the porosity of the receptacle
is selected so that the bleaching composition is substantially
all released from the receptacle before all the water is
evaporated from the fabrics. Moreover, it is preferred that
the bleaching composition be released rapidly, but uniformly,
during the early stages of the drying cycle when sufficient
water is present on the fabrics to dissolve the bleaching
composition. If the bleach is dispensed onto the substantially
dried clothes late in the drying cycle, it is either lost by
venting from the dryer, or can appear as undesirable dust on
the dried fabrics~
The preferred receptacles herein release the
particulate bleaching composition during the first one-
quarter of the drying cycle, when the fabrics are still
quite damp. In conventional home dryers, this preferred
period comes within the first 10 minutes to 15 minutes of
2~ the drying cycle.
leachinq Process
The process herein is carried out in the following
manner. Damp fabrics, usually containing from about 1 to
1.5 times their weight of water, are placed in the drum of
an automatic clothes dryer. In practice, such damp fabrics
are commonly obtained by laundering, rinsing and spin-drying
in a standard washing machine. The bleaching composition




- 14 -


, .

~5~ ~ ~7

herein is simply spread uniformly over all fabric surfaces,
for example, by sprinkling the composition onto the fabrics
from a shaker device. The dryer is then operated in standard
fashion to dry the fabrics, usually at a temperature of from about
50C to about 80C for a period of from about 10 minutes to
about 60 minutes, depending on the fabric load and type.
The bleaching process of the present invention is
carried out using an effective amount of the bleaching
compositïons of the type described above. By an
~'effective amount" of the bleaching composition herein is
meant an amount sufficient to bleach the stains from an
average load of-fabrics in an automatic dryer. Of course,
the actual amount of the bleaching composition employed
will depend on the fabric load, the amount of stain to
be removed, and the bleaching composition selected for use.
For an average 5 lbs. to 8 lbs. load of medium-to~heavily stained
fabrics, from about 10 grams to about 50 grams, preferably 20-30
grams, of bleaching composition suffice to provide good stain removal
In a preferred mode, the present process is carried
out by fashioning a bleaching article-comprising a receptacle
of the type hereinabove described containing an effective
amount of the bleaching composition. The bleaching article
is simply added to clothes dryer together with the damp
fabrics to be bleached. The tumbling action of the revolving
dryer drum evenly distributes the bleaching composition
over all fabric surfaces.
A preferred article useful in the present process
is one wherein the rate of release of the bleaching composition


- 15 -



.... . ~

11~5~ j7

is optimized. The rate of release should not be so fast
- that the bleach is deposited in an uneven manner on the
fabrics. Conversely, the rate of release of the bleaching
composition from the receptacle must not be too slow, since
S all, or substantially all, of the bleach is preferably
dispensed onto the fabrics while they are still damp. The
rate of release of the bleaching composition depends on both
the porosity of the openings in the receptacle and the
particle size of the bleaching composition. Of course, the
average diameter of the particles of bleaching composition
must be somewhat smaller than the average pore diameter of
the porous openings in the receptacle to achieve release.
Moreover, the bleaching compositions of the present invention
are employed as fine powders or dusts which rapidly dissolve
in the limited amount of water available in the damp fabrics.
Bleaching compositions having an average particle diameter
below about 200 ~, and preferably falling in the range from
about 25 ~ to about 175 ~ are rapidly dissolved in water
and are preferred for use herein. Accordingly, receptacles
having a pore diameter somewhat larger, ca. 5%-10% larger,
than the particle diameter o~ the bleaching compositions
provide controlled, even release.
Preferred articles herein are fashioned from open
pore polyurethane foam receptacles. The polyurethane foams
employed herein can be defined in terms of average pore
diameter, and polyurethane foams having rigorously controlled
pore sizes are commercially available. However, such
materials are quite expensive as compared with the common



- 16 -

1~5S~
open pore polyurethanes having mixed pore diameters. The
common open pore polyurethanes are more often characterized
in terms of their density in lbs./cu.ft. The density of
polyurethane foams depends almost wholly on the size of
the void spaces therein, and these void spaces are fairly
regular in size. Accordingly, by designating the density
of the polyurethane foams employed herein, the pore sizes are
necessarily defined. Open pore polyurethane foams having
a density of from about 0.75 lbs./cu.ft. to about 1.5 lbs./
~0 cu.ft. are useful herein.
In addition to the density of the polyurethane foam
and the particle size of the bleaching compositions herein,
the thickness of the polyurethane foam will affect the rate
of dispensing. It is preferred that the bleaching composition
be substantially completely dispensed onto the damp fabrics
within the first 10-15 minutes of the drying cycle. Poly-
urethane foams having a density from about 0.75 lbs/cu.ft.
to about 1.5 lbs./cu.ft. and a thickness of from about 0.10 in.
to about 0.50 in. when used in combination with bleaching
. compositions having the above-described particle sizes,
provide this preferred rate of release.
The dispensing receptacles which are conveniently
used in the present process can be provided in a variety of
sizes and shapes, and the particular configuration of the
receptacle is not critical to the practice of the invention.
For example, the receptacle herein can be provided wherein
only one wall, or a portion of one wall, comprises a porous
opening through which the bleaching composition is dispensed.




- 17 -


5~ 7
Preferably, the whole of the receptacle comprises a porous
material through which the bleaching composition sifts in
a manner akin to a rosin bag.
The simplest and most highly preferred bleaching
s article used in the present process employs the dispensing
receptacle in the form of a pouch. Preferred receptacles
herein comprise an open pore polyurethane foam pouch con-
taining the bleaching composition. The pouch is formed by
folding the polyurethane sheet into the desired pouch or
~0 pouch-like configuration and sealing the edges, for example
by heat-sealing. The bleaching composition is added through
the pouch by the top opening, and the opening is then sealedO
The resulting pouch is found to release the bleaching
composition through its porous walls upon agitation, e.g.,
J5 by the tumbling action of an automatic dryer.
In a highly preferred mode of the present process,
stains are removed from damp fabrics in an automatic dryer
by commingling said damp fabrics under heat in a clothes
dryer together with a dispensing means comprising a water-
insoluble, closed, open pore polyurethane pouch having a
density of from about 1.1 lbs./cu.ft. to about 1.30 lbs./cu.ft.
and a thickness of from about 0.15 in. to about 0.35 in., said
pouch containing a bleaching composition consisting essentially
of a mixture of sodium perborate and TAGU, said bleaching
~5 composition having an average particle diameter below about
150 ,u. ' '
The following examples illustrate the present invention
but are not intended to be limiting thereof.



- 18 -

.3..0S~ 7
Exam~le 1
Bleaching Compo_ition
Inyredient W
Sodium perborate 66.67
TAGU* 33-33

* As defined hereinabove




--19-- '

~5'3~i7
The sodium per~orate was screened through a 100
mesh screen (149 u) and the coarse particles which
did n~ pass through the screen were discarded.
The bleaching composition was prepared by admixing
18.67 qrams of the screened perborate and 9.33 grams of
TAGU. The resulting bleaching composition had an average
particle size below about 150 ~.
The bleaching composition prepared in the foregoing
manner was placed in a polyurethane (density 1.2 lbs./cu. ft.)
pouch formed from a piece of open pore polyurethane 7 in. x 5 in.
The polyurethane was 1/4 in. thick. This bleaching article
was employed in a through-the-dryer bleaching operation
and compared with commercial bleaching compositions employed
in a standard through-the-wash bleaching operation.
The testing procedure used to evaluate the bleaching
process employing the pouch article of Example I was as
follows ~ Five lbs. of terry wash cloths were placed in
a Kenmo Washer, Model 110, together with eight uniform
(5.0 in. x 5.0 in.) cotton cloth swatches stained with
standardized tea, coffee and brown gravy stains. The stained
swatches were intermingled with the terry wash cloths prior
to washing to simulate the type of treatment that would be
encountered in a standard washing procedure involving patches
of heavy stain on clothing. In the test procedure, four
swatches were stained with tea, two with coffee and two with
brown gravy. The washer was operated under the manufacturer's
suggested operating conditions using 17 gallons of wash




- 20 -

~ .

~is~
water of 7 grain hardness at a temperature of about 125F
in the wash cycle. 70 Grams of a standard commercial
built anionic detergent composition were employed to
launder the fabrics. Four separate washer runs, denoted
as Runs A through D were made.
In Run A, a chlorine bleach was added to the rinse
cycle through a bleach dispenser in the manner recommended
by the manufacturer. The commercial bleach was employed
at a concentration of 200 ppm of available chlorine.
In Run B, 103 grams of a co~mercial sodium perborate
bleaching composition were added to the laundering liquor
in accordance with the washer manufacturer's recommended
procedure. This amount of bleaching composition was calculated
to provide 55 ppm of available oxygen in the wash liquor.
Runs C and D involved only laundering, rinsing~ and
spin-drying the fabric bundle, without added bleach.
The fabric bundles of Runs A, B and C were dried
in a standard commercial dryer using the manufacturer's
recommended procedure.
The spun-dried, damp fabrics of Run D were placed in
a commercial dryer together with the article of Example I.
The fabrics were dried according to the manufacturer's
operating instructions.
The standard stain swatches were separated from the
terry towels and their degree of whiteness was evaluated using
a Hunter Colc and Color Difference Meter, in combination with a
Roland, Robinson readout device (Model AS/026), and the L, a
and b values thereby obtained were substituted in the whiteness



- 21 -

~ ~5~ti,'i'
equation derived in a manner analogous to the whiteness
equation in the article by F. Diehl, "A Single Number
Expression for Whiteness Evaluation of Washed Fabrics",
in P eedings of the IV International Conqress on Surface
Active Substances, Brussels, 7-12 September, 1964, Vol. III,

. . .= . _ _
section C of the Congress.
This whiteness equation,

/ \1/2
W = 100 - ~(100-L)2 + 1.44 [(a-4.1)2 + (b+8.0)

is especially adapted for modern fabrics with fluorescent
whitening agents.
The bleaching results from the test are set forth in
Table I. The higher the number in the table, the more
efficient is the bleaching. Two units on the Diehl scale
have been shown to be visually recognizable by the average
observer.




- 22 -

~ ~5~ 7

_ABLE I


Brown 3 Stain
Coffee GravyTea Avera~e
Run A 9.0 6.918.9 11.6
Run B 3.5 1.4 2.9 2.6

Run C O
(control)

Run D 8.6 2.5 9.7 7.0
(Dryer Bleach)
As can be seen from Table I, Run D, involving the
dryer added bleach employed in the manner of this invention,
provides more effective stain removal than a commercial
perborate bleach employed in an aqueous laundering liquor.
Moreover, the bleach herein compared favourably with a
commercial chlorine bleach used in an aqueous medium.




-23-


Examplc II

Bleachinq Composition
Inqredient Wt. o/O
_
Sodium perborate . 65
!, TAGU 32.5
bls-(styrylsulfonate)biphenyl* 0.7
Perfume 1.7

*Optical Brightener




_ 24 -

~3~

The sodium perborate (as the commercial tetrahydrate)
is screened through a 100 mesh screen and the particles
which are too large to pass through the screen are discarded.
The TAGU, sodium perborate, optical brightener and perfume
are dry-mixed and sieved through a second 100 mesh screen
to provide a bleaching composition having an average
particle diameter belo~ about 150 ~.
Eight lbs. of damp fabrics containing a total of
ca. 12 lbs. of water and stained with miscellaneous food
stains are placed in an automatic dryer at ambient temperature.
The fabrics are spread out uniformly on the bottom of the
dryer drum. 25 Grams of the composition of Example II are
placed in a pouch fashioned from open pore polyurethane having
a density of 1.2 lbs./cu. ft. and a wall thickness of 1/4 in.
The pouch is sealed with a plastic clip and placed on top
of the damp fabrics. The dryer is operated at an average
temperature of 60C, with tumbling, for 60 minutes. During
this time, the bleaching composition sifts onto all
fabric surfaces in a uniform manner. The fabrics are
removed from the dryer and the food stains are found to be
evenly and uniformly bleached.
The bleaching composition of Example II is replaced
by an equivalent amount of ammonium perborate and TAGU at
a 1:1 weight ratio; a 1:1:1 wt. mixture of sodium perborate,
TAGU, and ~-methoxyperbenzoic acid, a 1:1:1: wt. mixture
of sodium perborate, Oxone, and TAGU; and chlorinated
trisodium phosphate, respectively, and equivalent bleaching
results are secured.


- 25 -

1~)5'~

In the procedure of Example II the polyurethane
foam pouch is replaced by a cotton bag woven to provide
200 ~ openlngs along one side of the bag. The bleach
is evenly dispensed onto the fabrics and even, effective
bleaching is secured.
In the foregoing procedure, the bleaching composition
is replaced by equivalent perborate/TAGU bleaches having
particle diameters of 50 ~, 100 ~ and 175 ~, respectively
and even, effective bleaching is secured.
As can be seen from the foregoing, the bleaching
process herein takes advantage of the fact that fabrics
which are laundered and spun dry in an automatic washer
retain from 25 % to 300~ be weight of water, based on
total fabric weight. The bleaching compositions used in
the process herein are formulated as small particles which
rapidly dissolve in the water available from the damp
fabrics. The resulting concentrations of bleach at the
fabric surface, i.e., at the site of the stains, is
quite high. For the peroxygen bleaches herein, from about
300 ppm to about 5000 ppm of available 2 per gram of
fabric are provided, and this high concentration of bleach
effectively removes a wide variety of fabric stains.
What is claimed is:

Representative Drawing

Sorry, the representative drawing for patent document number 1059267 was not found.

Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 1979-07-31
(45) Issued 1979-07-31
Expired 1996-07-31

Abandonment History

There is no abandonment history.

Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
THE PROCTER AND GAMBLE COMPANY
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

To view selected files, please enter reCAPTCHA code :



To view images, click a link in the Document Description column. To download the documents, select one or more checkboxes in the first column and then click the "Download Selected in PDF format (Zip Archive)" or the "Download Selected as Single PDF" button.

List of published and non-published patent-specific documents on the CPD .

If you have any difficulty accessing content, you can call the Client Service Centre at 1-866-997-1936 or send them an e-mail at CIPO Client Service Centre.


Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Description 1994-04-23 26 847
Drawings 1994-04-23 1 7
Claims 1994-04-23 2 64
Abstract 1994-04-23 1 13
Cover Page 1994-04-23 1 15